 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.wizards.datatransfer;

 import java.util.ArrayList ;
 import java.util.Iterator ;
 import java.util.List ;

 import org.eclipse.jface.operation.ModalContext;
 import org.eclipse.ui.dialogs.FileSystemElement;
 import org.eclipse.ui.internal.wizards.datatransfer.MinimizedFileSystemElement;

 /**
  * The PopulateFilesOperation is an operation used to populate a FileSystemElement one
  * level deep rather than the whole way.
  */
 public class PopulateRootOperation extends SelectFilesOperation {
     /**
      * Create a new <code>PopulateFilesOperation</code>.
      * @param rootObject the object to be populated
      * @param structureProvider the object that defines how we are to populate it.
      */
     public PopulateRootOperation(Object rootObject,
             IImportStructureProvider structureProvider) {
         super(rootObject, structureProvider);
     }

     /**
      * Creates and returns a <code>FileSystemElement</code> if the specified
      * file system object merits one. The criteria for this are:
      * - if the file system object is a container then it must have either a
      * child container or an associated file
      * - if the file system object is a file then it must have an extension
      * suitable for selection
      */
     protected FileSystemElement createElement(FileSystemElement parent,
             Object fileSystemObject) throws InterruptedException {

         //Iterate on level deep
 return createElement(parent, fileSystemObject, 2);

     }

     /**
      * Creates and returns a <code>FileSystemElement</code> if the specified
      * file system object merits one. The criteria for this are:
      * - if the file system object is a container then it must have either a
      * child container or an associated file
      * - if the file system object is a file then it must have an extension
      * suitable for selection
      * recurse down for depth to populate children
      */
     protected FileSystemElement createElement(FileSystemElement parent,
             Object fileSystemObject, int depth) throws InterruptedException {
         ModalContext.checkCanceled(monitor);
         boolean isContainer = provider.isFolder(fileSystemObject);
         String elementLabel = parent == null ? provider
                 .getFullPath(fileSystemObject) : provider
                 .getLabel(fileSystemObject);

         MinimizedFileSystemElement result = new MinimizedFileSystemElement(
                 elementLabel, parent, isContainer);
         result.setFileSystemObject(fileSystemObject);

         if (isContainer) {
             if (depth > 0) {
                 List children = provider.getChildren(fileSystemObject);
                 if (children == null) {
                     children = new ArrayList (1);
                 }
                 Iterator childrenEnum = children.iterator();
                 while (childrenEnum.hasNext()) {
                     createElement(result, childrenEnum.next(), depth - 1);
                 }
                 result.setPopulated();
             }

         }

         return result;
     }
 }

